2023 Commercial Electrical Inspector – Practice Exam

2023 Commercial Electrical Inspector

80 Questions

3.5 Hours

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1. What action is a listed interactive inverter permitted to take, instead of automatically disconnecting all ungrounded conductors, when one or more phases of the interconnected primary source opens?

A) Trip or shall be permitted to automatically cease exporting power.

B) Automatically disconnect only the phase conductors.

C) Automatically signal a malfunction.

D) Automatically revert to stand-alone mode.

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2. Feeder or branch circuits for a swimming pool installed in a corrosive environment must contain an insulated copper equipment grounding conductor (EGC) not smaller than which size?

A) 14 AWG

B) 12 AWG

C) 8 AWG

D) 10 AWG

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3. Short sections of raceways used to provide support or protection of cable assemblies from physical damage are NOT required to be what?

A) Made electrically continuous

B) Secured at both ends

C) Readily accessible

D) Made of rigid metal

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4. What is the maximum interval permitted for securing LFNC when installed in lengths exceeding 1.8 m (6 ft)?

A) 900 mm (3 ft)

B) 1.2 m (4 ft)

C) 600 mm (2 ft)

D) 1.4 m (4 1/2 ft)

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5. For maintenance of a wind turbine, all 125-volt, single-phase, 15- and 20-ampere receptacles installed for this purpose must have what specific protection?

A) Surge protection

B) Ground-fault circuit-interrupter protection for personnel

C) Arc-fault circuit-interrupter protection

D) Overcurrent protection only

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6. When is a grounding electrode system and GEC NOT required for a building supplied by a feeder or branch circuit?

A) If only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor

B) If the building is located within 3.0 m (10 ft) of the main service

C) If the feeder conductors are ungrounded

D) If the supply is less than 600 volts

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7. Type 3 SPDs are permitted to be installed on the load side of branch-circuit overcurrent protection up to the equipment served. If specified in manufacturer’s instructions, what is the minimum conductor distance required from the service or separately derived system disconnect?

A) 6 m (20 ft)

B) 7.5 m (25 ft)

C) 10 m (30 ft)

D) 3 m (10 ft)

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8. In other than one- and two-family dwellings, where must a sign be placed for an Optional Standby Power Source?

A) At the building entrance

B) At the main panelboard

C) At the service equipment

D) At the transfer switch

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9. Is the installation of conductors permitted in cellular metal floor raceways in any hazardous (classified) location?

A) Only in Class I, Division 2 locations

B) No, except as permitted by other articles in this Code

C) Yes, if totally enclosed

D) Yes, if the voltage is 600V or less

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10. Where structural members do not readily permit fastening RMC within 900 mm (3 ft) of a termination point, the fastening distance shall be permitted to be increased to what maximum distance?

A) 3.0 m (10 ft)

B) 1.8 m (6 ft)

C) 2.0 m (6 ft 7 in.)

D) 1.5 m (5 ft)

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11. For track lighting in commercial occupancies, what is the additional load that must be included for every 600 mm (2 ft) of lighting track or fraction thereof?

A) 150 volt-amperes

B) 180 volt-amperes

C) 120 volt-amperes

D) 90 volt-amperes

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12. If a conductor in a cable assembly operating at 120 volts has a gray outer finish and is reidentified for use as an ungrounded conductor, what color can the reidentification marking NOT be?

A) Brown

B) Blue

C) Red

D) White, gray, or green

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13. Inverter output circuits are permitted to occupy the same junction box, pull box, or wireway with Solar PV system DC circuits, provided they are grouped and identified as required by which subsections?

A) 690.31(B)(2) and (B)(3)

B) 690.7 and 690.8

C) 690.12 and 690.41

D) 690.15 and 690.23

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14. Where a portable optional standby source is used as a nonseparately derived system, what action must be taken regarding the equipment grounding conductor?

A) The equipment grounding conductor shall be bonded to the system grounding electrode.

B) A separate grounding electrode is required at the generator.

C) The equipment grounding conductor must be sized 2 AWG larger.

D) It must be isolated from the source grounding electrode.

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15. If a Flow Battery System experiences an electrolyte leak, what safety measure must be provided?

A) A secondary containment system only.

B) Automatic neutralization of the electrolyte.

C) A shutdown of the battery electronics.

D) An alarm system shall be provided to signal an electrolyte leak from the system.

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16. For conductors and live parts up to 22 kV or less to ground, what is the minimum vertical clearance required over roofs or projections that are NOT readily accessible to people?

A) 4.1 m (13.5 ft)

B) 3.5 m (11.5 ft)

C) 3.8 m (12.5 ft)

D) 3.0 m (10.0 ft)

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17. For raceways or cables exposed to direct sunlight on or above rooftops, if the distance above the roof to the bottom of the raceway or cable is less than 19 mm (3/4 in.), what temperature adder shall be applied to the outdoor temperature?

A) 33°C (60°F)

B) 28°C (50°F)

C) 30°C (54°F)

D) 25°C (45°F)

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18. Arc-fault circuit-interrupter type and ground-fault circuit-interrupter type replacement receptacles shall be installed in what type of location?

A) An enclosed, non-ventilated space

B) A readily accessible location

C) Within 5 ft. of the service panel

D) A dry location

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19. What type of conductor material shall be used to carry current unless otherwise provided in this Code?

A) Aluminum or steel

B) Copper, aluminum, or copper-clad aluminum

C) Silver-plated copper

D) Nickel, silver, or platinum

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20. Which two markings are required on all nonlocking-type, 125 volt , 15text{-} and 20(ampere) receptacles controlled by an automatic control device?

A) The word “interrupted” and a power symbol

B) The word "Energy Saver" and the ampere rating

C) The word "Automatic" and the voltage rating

D) The symbol shown in Figure 406.3(F)} and the word “controlled”

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21. For individual open conductors exposed to the weather and operating at 1000 volts, what is the minimum required distance between supports when conductors are separated by 150 mm (6 in.)?

A) 1.4 m (4 1/2 ft)

B) 1.8 m (6 ft)

C) 4.5 m (15 ft)

D) 2.7 m (9 ft)

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22. Enclosures for overcurrent devices shall generally be mounted in a vertical position, but listed busway plug-in units are permitted to be mounted in which orientation?

A) Only horizontally

B) Orientations corresponding to the busway mounting position

C) Only vertically if the enclosure is less than 2.0 m (6 ft 7 in.) from the floor

D) Upside down if labeled for such use

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23. What type of loads are prohibited on impedance grounded systems operating between 480 volts and 1000 volts?

A) Line-to-neutral loads

B) Motor loads

C) Noncontinuous loads

D) Continuous loads

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24. Where grounding-type receptacles are supplied through a GFCI in a replacement scenario lacking an equipment grounding conductor, the receptacle or cover plate must be marked “GFCI Protected” and with which other visible marking?

A) “Limited Access”

B) “Copper Conductors Only”

C) “Caution: Unbalanced Load”

D) “No Equipment Ground”

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25. A handhole is not required in a pole 8 ft. or less in height abovegrade if the supply wiring method continues without splice or pull point, and access to the interior is gained by removing what?

A) The luminaire

B) The pole cover

C) The pole base

D) The foundation

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26. If fuses are of the type that can be operated as a disconnecting switch, a set of such fuses shall be permitted to be used as what specific component in the service installation?

A) The isolating switch

B) The short-circuit protective device

C) The transfer switch

D) The load interrupter

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27. For a separately derived system, where must the SPD be connected?

A) Anywhere on the load side of the main bonding jumper

B) On the supply side of the transformer

C) On the load side of the first overcurrent device in the separately derived system

D) In the nearest panelboard

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28. Outlet boxes or fittings used at luminaire or lampholder outlets on a vertical surface that are permitted to support a luminaire weighing more than 23 kg (50 lb) must be marked on the interior of the box to indicate what?

A) The date of installation

B) The maximum weight of the luminaire permitted to be supported by the box

C) The maximum voltage supported

D) The name of the installer

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29. Conductors tapped to a feeder shall be permitted to be protected by the feeder overcurrent device where that device also protects what other component?

A) The grounded conductor

B) The utilization equipment

C) The main service disconnect

D) The tap conductor

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30. What type of branch circuits supplying egress lighting, life-critical stunts, or life-critical special effects shall not be protected by GFCIs?

A) General lighting

B) Egress lighting, life-critical stunts, life-critical special effects, or any other condition where a nonorderly shutdown might introduce additional or increased hazards

C) Convenience outlets

D) Audience seating areas

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31. Are reconditioned reactors permitted to be installed on electrical circuits?

A) No, they must be new

B) Only if rated over 1000Volts

C) Only if they comply with Article 450

D) Yes, reconditioned reactors shall be permitted

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32. What type of current, such as that resulting from required grounding and bonding connections, is NOT classified as objectionable current?

A) Direct currents from cathodic protection systems

B) Currents resulting from electromagnetic interference

C) Currents resulting from required grounding and bonding connections

D) Currents resulting from ground faults

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33. Which cable listed in Table 400.4 is permitted for use in wet locations and is characterized by Extra-hard usage?

A) Type C Lamp cord

B) Type PD Twisted portable cord

C) Type HPD Heater cord

D) Type EV Electric vehicle cable

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34. What must be provided about service equipment, switchboards, and motor control centers that are installed indoors?

A) Automatic light control

B) Emergency lighting only

C) Switched receptacles

D) Illumination for all working spaces

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35. For a grounded system, if the substantial structure supporting service conductors over a roof is metal, it shall be bonded by means of a bonding jumper and listed connector to where?

A) The grounded overhead service conductor

B) The structural steel

C) The building neutral bus

D) The equipment grounding conductor

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36. What must be available to the authority having jurisdiction regarding the ground-fault protection system testing?

A) A video recording of the test

B) The test equipment calibration certificate

C) The test equipment identification number

D) A written record of this testing

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37. What is the minimum nominal insulation thickness in mils for Type HF ECTFE fixture wire?

A) 30 (mils)

B) 20 (mils)

C) 15 (mils)

D) 5.5 (mils)

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38. In industrial installations only, secondary conductors not over 7.5 m (25 ft) long are permitted without protection at the secondary connection if the sum of the ratings of the overcurrent devices does not exceed what value?

A) The maximum connected load

B) The secondary current rating of the transformer

C) 125 percent of the connected load

D) 80 percent of the feeder conductor ampacity

39 / 80

39. For adjustable-speed drive systems rated over 1000 Volts, the conductors supplying the power conversion equipment must have an ampacity not less than what percentage of the rated input current to the power conversion equipment?

A) 115 percent

B) 125 percent

C) 100 percent

D) 120 percent

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40. Field-assembled extension cords and multiconductor cable assemblies consisting of listed connectors and cable are permitted in what specific areas of studios and remote locations?

A) Support areas

B) Production areas

C) Dressing rooms

D) Administrative offices

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41. When splicing conductors by soldering, what must occur before the splice is soldered?

A) An approved splicing device must be installed.

B) The splice must be pre-heated with a torch.

C) The conductors must be lubricated with flux.

D) The conductors must first be spliced or joined so as to be mechanically and electrically secure without solder.

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42. All energized equipment parts located in the fire pump room must be located at least what minimum distance above the floor level?

A) 300 mm (12 in.)

B) 50 mm (2 in.)

C) 100 mm (4 in.)

D) 200 mm (8 in.)

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43. How many 120-volt, 20-ampere branch circuits must be provided to supply the required bathroom receptacle outlet(s) and any countertop and similar work surface receptacle outlets in a dwelling unit?

A) One or more circuits dedicated to the bathroom outlets

B) One circuit per bathroom

C) At least two dedicated circuits

D) A single circuit, which may supply general lighting

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44. Equipment having an open circuit voltage exceeding 1000 volts shall not be installed in or on which type of occupancy?

A) Commercial occupancies

B) Dwelling occupancies

C) Educational occupancies

D) Industrial occupancies

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45. When establishing a new Legally Required Standby System, who is responsible for conducting or witnessing the commissioning of the complete installed system?

A) A licensed professional engineer

B) The authority having jurisdiction

C) The electrical contractor of record

D) The system owner or manager

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46. The requirement for Ground-Fault Protection for Personnel (590.6) applies to temporary wiring installations used to supply temporary power to equipment used by personnel during which activities?

A) Holiday decorative lighting only

B) Emergencies and tests only

C) Construction, remodeling, maintenance, repair, or demolition

D) Developmental work only

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47. Ground-fault protection of equipment is required for each service disconnect rated how many amperes or more?

A) 600 amperes

B) 800 amperes

C) 1000 amperes

D) 400 amperes

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48. Cords and cables used for supply to border lights, drop boxes, and connector strips shall be listed for what specific usage rating?

A) Standard usage

B) Hard usage

C) Extra-hard usage

D) Intermittent usage

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49. For transformers rated over 1000 Volts with impedance not more than 6 percent , what is the maximum permissible primary circuit breaker setting in any location?

A) 600 percent

B) 500 percent

C) 400 percent

D) 300 percent

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50. An insulated copper equipment grounding conductor, identified along its entire length by green insulation, must be connected to the non-current-carrying conductive surfaces of fixed electrical equipment likely to become energized operating at what minimum voltage?

A) Over 100 Volts

B) Over 75 Volts

C) Over 120 Volts

D) Over 50 Volts

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51. The two to six service disconnects permitted must be grouped, with the exception of one disconnect used only for which specific equipment?

A) Fire alarm panel

B) A water pump also intended to provide fire protection

C) Elevator control

D) Electric vehicle charging

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52. Solid aluminum conductors of what AWG sizes must be made of an AA-8000 series electrical grade aluminum alloy conductor material?

A) 12, 14

B) 8, 10, 14

C) 10, 12

D) 8, 10, and 12 AWG

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53. Conductors shall not be associated together in such a way that the limiting temperature of the conductors is exceeded with respect to the kind of circuit, the number of conductors, or which other factor?

A) Type of insulation material

B) Location of the enclosure

C) Maximum length of run

D) The wiring method used

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54. How shall bends in NUCC be made?

A) Using only factory elbows

B) By identified bending equipment

C) With a minimum radius of 10 times the conduit diameter

D) Manually, so that the conduit will not be damaged and the internal diameter is not reduced

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55. Boxes that enclose devices or utilization equipment supplied by conductors larger than 4 AWG must be identified for what?

A) High fault current

B) Their specific function

C) Use in wet locations

D) Noncombustible applications

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56. What is the minimum fire rating required for the walls and roof of an electrical vault?

A) 3 hours

B) 2 hours

C) 1 hour

D) 4 hours

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57. What is the minimum ampere rating of the feeder assembly or service-entrance conductors that the manufacturer must provide in the written installation instructions for manufactured homes?

A) Not less than 50 amperes

B) Not less than 100 amperes

C) Not less than the minimum load calculated in accordance with 550.18

D) Not less than 80 percent of the feeder capacity

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58. For indoor electrical equipment rated not over 1000 volts, which enclosure type provides protection against incidental contact, falling dirt, falling liquids/light splashing, and circulating dust, lint, fibers, and flyings, but NOT protection against hosedown?

A) Type 12

B) Type 4X

C) Type 6

D) Type 4

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59. When must the markings on flexible bus systems be visible?

A) After installation

B) Before ordering

C) Only during installation

D) Only during maintenance

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60. The 38 mm (1 1/2 in.) spacing requirement under metal-corrugated sheet roof decking is NOT required if the roof decking is covered with a minimum thickness of what material?

A) 25 mm (1 in.) rigid insulation

B) 50 mm (2 in.) concrete slab

C) 32 mm (1 1/4 in.) gravel

D) 45 mm (1 3/4 in.) wood decking

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61. Interconnection between a surge arrester protecting a transformer and the secondary grounded circuit conductor or grounding electrode conductor requires a metal interconnection if what additional grounding connection exists?

A) A grounding connection in the utility vault

B) A connection to the building steel

C) A continuous connection to the equipment ground terminal

D) The grounded conductor of the secondary has a grounding connection elsewhere to a continuous metal underground water piping system

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62. For cord- and attachment-plug-connected motor-compressors used on 15text{-} or 20(ampere), 120 volt , or 15(ampere), 208text{-} or 240 volt , single-phase branch circuits, what is the maximum ampere rating permitted for the attachment plug and receptacle or cord connector at 250 Volts?

A) 15(amperes)

B) 30(amperes)

C) 20(amperes)

D) 25(amperes)

63 / 80

63. Aircraft energizers (external power sources for aircraft) must be designed and mounted such that all electrical equipment and fixed wiring will be at least what minimum height above floor level?

A) 10 ft. above floor level

B) 3 ft. above floor level

C) 18(in.) above floor level

D) 5 ft. above floor level

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64. Fixed electric space-heating loads shall be calculated at what percentage of the total connected load?

A) 100 percent

B) 75 percent

C) 90 percent

D) 80 percent

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65. Where service heads or goosenecks cannot be located above the point of attachment of the service conductors, the service head or gooseneck location shall be permitted not farther than what maximum distance from the point of attachment?

A) 600 mm (24 in.)

B) 450 mm (18 in.)

C) 1.2 m (4 ft)

D) 900 mm (36 in.)

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66. What general form is NUCC provided in?

A) Custom-sized rigid lengths

B) Components sold separately for field assembly

C) An assembly that is provided in continuous lengths shipped in a coil, reel, or carton

D) 3-meter (10 ft) pre-cut lengths

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67. Where shall splices and taps be made in cellular concrete floor raceways?

A) Only in header access units or junction boxes

B) Only in the cells

C) Only in listed splice kits

D) Only at the distribution panel

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68. Cablebus shall be protected against overcurrent in accordance with the ampacity of the cablebus conductors as specified in which NEC section?

A) 240.6

B) 310.14

C) 240.21

D) 240.4

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69. What demand factor percentage applies to the remainder of general lighting load over 120,000 VA in a Dwelling Unit?

A) 50 percent

B) 25 percent

C) 35 percent

D) 100 percent

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70. Outdoor overhead conductors over 1000 volts are permitted for what three circuit types?

A) Only feeders and branch circuits

B) Service conductors, feeders, or branch circuits

C) Only services and feeders

D) Only services and branch circuits

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71. The continuous current rating of a circuit breaker shall not be less than what value?

A) The short-circuit current rating

B) The maximum continuous current through the circuit breaker

C) 125 percent of the continuous load

D) 80 percent of the conductor ampacity

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72. For a service rated 200 amperes supplying the entire load associated with a one-family dwelling, what is the minimum required size for aluminum or copper-clad aluminum service conductors, if no adjustment or correction factors are required?

A) 3/0 AWG

B) 2/0 AWG

C) 4/0 AWG

D) 250 kcmil

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73. When nonmetallic-sheathed cables pass through holes in metal framing members, how must the cable be protected?

A) By insulating tape wrapped around the cable

B) By a steel plate at least 1.6 mm (1/16 in.) thick

C) By rigid metal conduit sleeves

D) By listed bushings or listed grommets covering all metal edges

74 / 80

74. In supervised industrial installations (Part VIII), where the overcurrent device is rated over 800 amperes, the ampacity of the conductors it protects shall be equal to or greater than what percentage of the rating of the overcurrent device?

A) 92.5 percent

B) 80 percent

C) 90 percent

D) 95 percent

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75. For motor-driven electric space-heating equipment with a motor rated over 1/8(hp) and without supplementary overcurrent protection, a disconnecting means shall be located where?

A) At the service entrance

B) In the adjacent room

C) Within sight from the motor controller or permitted to comply with 424.19(A)(2)}

D) At the panelboard

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76. The size of the DC system bonding jumper shall not be smaller than what conductor?

A) The system grounding electrode conductor specified in 250.166

B) 4 AWG copper

C) The neutral conductor

D) The largest derived ungrounded conductor

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77. Type S adapters shall be designed so that once inserted in a fuseholder, they cannot be what?

A) Replaced

B) Removed

C) Locked

D) Shunted

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78. When installed at services, Type 1 SPDs shall be connected to which of the following locations?

A) The ungrounded service conductor

B) The load side of the service overcurrent device

C) The main bonding jumper

D) The Grounding electrode for the service

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79. How must the grounded conductor of a mineral-insulated, metal-sheathed cable (Type MI) be identified at the time of installation?

A) By a label applied mid-span showing the voltage

B) By a distinctive white or gray marking that encircles the conductor insulation at its terminations

C) By a continuous blue stripe

D) By a green tag at the enclosure

80 / 80

80. For Type ACT cable, where is a moisture-resistant fibrous covering required?

A) Only on the individual conductors

B) On all conductors and the outer armor

C) On the internal bonding strip

D) Only on the outer armor

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2023 Commercial Electrical Inspector – Practice Exam

“This full-length timed practice exam replicates real ICC testing conditions, challenging you with randomized questions and strict time limits to measure your readiness under true exam pressure.”